Diffusion transfer photographic film unit

Abstract

A self-developing diffusion transfer photographic film unit which includes a latent image which becomes visible upon photographic processing of the film unit. The latent image is formed with a chemical compound such as an indicator dye and the visible image formed from the latent image as a result of photographic processing may be transient or permanent. Also described are diffusion transfer photographic methods.

What is claimed is:  
     
       1. A diffusion transfer photographic film unit comprising a photosensitive element comprising a support carrying at least one silver halide emulsion layer; 
       a second sheet-like element which is in superposed relationship or adapted to be placed in superposed relationship with said photosensitive element;  
       an image-receiving layer positioned in one of said photosensitive and second sheet-like elements;  
       means providing an aqueous alkaline processing composition for distribution between predetermined layers of said elements,  
       and a latent image carried by at least one of said photosensitive and second sheet-like elements, said latent image comprising a chemical compound capable of forming a visible image upon contact with said aqueous alkaline processing composition, said chemical compound not being exposed silver halide.  
     
     
       2. The diffusion transfer film unit as defined in  claim 1  wherein said latent image comprises a chemical compound selected from the group consisting of indicator dyes, bleachable indicator dyes and bleachable filter dyes. 
     
     
       3. The diffusion transfer film unit as defined in  claim 1  wherein said latent image is carried by said imaging receiving layer. 
     
     
       4. The diffusion transfer film unit as defined in  claim 1  wherein said photosensitive element comprises a support carrying at least two different color image components, each of said color image components including a color-sensitive silver halide emulsion in association with a corresponding image dye-providing material. 
     
     
       5. The diffusion transfer film unit as defined in  claim 4  which includes a red-image component comprising a red sensitive silver halide emulsion layer in association with a cyan image dye-providing material, a green image component comprising a green-sensitive silver halide emulsion layer in association with a magenta image dye-providing material and a blue image component comprising a blue-sensitive silver halide emulsion layer in association with a yellow image dye-providing material. 
     
     
       6. The diffusion transfer film unit as defined in  claim 1  further including means providing a light-reflecting layer against which an image in said image-receiving layer may be viewed and wherein said second sheet-like element further includes a support and said image-receiving layer is positioned in said second sheet like element. 
     
     
       7. The diffusion transfer film unit as defined in  claim 6  wherein said support of said second sheet-like element is transparent and said support of said photosensitive element is opaque. 
     
     
       8. The diffusion transfer film unit as defined in  claim 7  wherein said latent image is carried by said image-receiving layer and comprises a bleachable indicator dye. 
     
     
       9. The diffusion transfer film unit as defined in  claim 6  wherein said support of said second sheet-like element is opaque, said means providing a light-reflecting layer is a layer of light-reflecting pigment positioned between said image-receiving layer and said opaque support of said second sheet-like element and said second sheet-like element is adapted to be separated from said photosensitive element after an image is formed in said image-receiving layer. 
     
     
       10. The diffusion transfer film unit as defined in  claim 9  wherein said latent image is carried by said image-receiving layer and comprises an indicator dye. 
     
     
       11. The diffusion transfer film unit as defined in  claim 1  wherein said means providing an aqueous alkaline processing composition comprises a rupturable container releasably holding said aqueous alkaline processing composition. 
     
     
       12. The diffusion transfer film unit as defined in  claim 1  wherein said latent image is adapted to form a transient visible image as a result of photographic development. 
     
     
       13. The diffusion transfer film unit as defined in  claim 1  wherein said latent image is adapted to form a permanent image as a result of photographic development. 
     
     
       14. A diffusion transfer photographic method comprising exposing a film-unit as defined in  claim 1  to an object and distributing said aqueous alkaline processing composition between predetermined layers of said film unit whereby there are provided as a result of photographic development a visible image corresponding to said latent image and a visible image corresponding to said object. 
     
     
       15. The diffusion transfer photographic method as defined in  claim 14  wherein said visible image corresponding to said latent image is transient. 
     
     
       16. The diffusion transfer photographic method as defined in  claim 14  wherein said visible image corresponding to said latent image is permanent.